upgrade test requirement org.mockito:mockito-core 3.0.0 -> 3.1.0

Author: TheSnoozer

maven/pom.xml

@@ -33,7 +33,7 @@
     <maven-plugin-plugin.version>3.6.0</maven-plugin-plugin.version>
 
     <junit.version>5.5.1</junit.version>
-    <mockito.version>3.0.0</mockito.version>
+    <mockito.version>3.1.0</mockito.version>
 
     <fest-assert.version>1.4</fest-assert.version>
   </properties>